If skies are clear Sunday night, the moon will look pretty ominous.
Every once in a while, the moon, the Earth and the sun move into the same path and the Earth’s shadow blocks light from getting to the moon. The moon turns a deep red color from all the dust particles in our atmosphere.
This phenomenon is called a “total lunar eclipse."
Steve Kawaler, an astronomy professor at Iowa State University, says unlike the 2017 total solar eclipse which could only be seen along a specific path in the country, the whole continent will be treated to Sunday's spectacle.
“The moon is the screen that the shadow is being projected upon,” Kawaler said. “And so we’re all sort of sitting in a movie theater watching the same movie.”
And unlike the 2017 total solar eclipse during which people donned glasses as they looked up at the sky, the lunar eclipse can be seen with the naked eye.
The eclipse will begin around 8:30 p.m. Sunday, peak at 11:12 p.m. and will end close to 1:50 a.m. Monday. The previous total lunar eclipse seen from Iowa was Jan. 31, 2018. It was cloudy out, Kawaler said.
Herb Schwartz, a lecturer at Drake Municipal Observatory in Des Moines, says these kinds of eclipses are a good opportunity to use math and science.
"One of the things you can see is the shadow of the Earth moving across the face of the moon," Schwartz said. "If you know how big the moon is, you could actually figure how fast that shadow is moving across the face of the moon. You can watch various points of craters or mountains on the moon slowly get covered. You could conceivably figure out the height of some of those mountains."
The upcoming lunar eclipse is being called a “super blood wolf moon." The “super moon” means that the moon looks bigger to the Earth, the “blood moon” means there is a lunar eclipse and the “wolf moon” is when a full moon happens in January. Schwartz says he objects to the use of these labels to describe the total lunar eclipse.
“It just evokes some kind of superstition and diabolical thing and it’s not,” Schwartz said. “It’s a natural event that happens predictably.”
Thousands of years ago, lunar eclipses were useful in tracing the shape of the Earth, Kawaler said. Now we know the Earth is round. But both Kawaler and Schwartz say lunar eclipses still provide plenty of opportunities for people to learn about space – if it’s clear enough to see it outside.
If it's clear, Drake Municipal Observatory will be open Sunday night. Scientists will be on site with a few telescopes so people can swing by to watch and learn about the eclipse.
The next total lunar eclipse visible in Iowa will happen May 26, 2021.